1. Field of the Invention
The present invention relates to a bridging system for expansion gaps in the roadbed surfaces of bridges or the like. The device comprises elastic sealing strips that extend transversely to the longitudinal direction of the road surface, and are disposed in each instance between parallel bearers, the uppermost surfaces of which bearers are level with the surface of the road surface. Each of the bearers is connected to a crosspiece, the crosspieces being arranged in groups, and supported in a recess beneath the roadway on both sides of the expansion gap so as to be able to move longitudinally. The longitudinal movement of the crosspiece is effected by means of a connecting rod, the ends of which are retained on opposite sides of the expansion gap.
2. Description of the Prior Art
A bridging system for expansion gaps, which involves the so-called forced control of the crosspieces, is disclosed in Swiss Patent No. 494316. In this gap bridging system the connecting rod is disposed beneath the crosspieces. Each crosspiece is provided with a trunnion that extends downwardly and engages in a longitudinal groove in the connecting rod via an interposed sliding block. When the width of the gap changes as a result of expansion or contraction of the adjacent components, the connecting rod that is disposed deep beneath the surface of the road has to move the crosspieces with the bearers that are lying upon them and which extend upwards as far as the surface of the road. In addition, when traffic that is passing over the gap bridging system either accelerates or brakes, forces will be transmitted to the bearers and from there to the crosspieces, the trunnions and the sliding blocks within the grooves to the connecting rods. Transmission of the forces that are occasioned by the moving traffic is thus effected through various support points with relatively long lever arms. The constant alternating effect of such forces leads to large amounts of wear at the support points. Worn supports and bearings generate a great deal of noise when the bridging system is driven over.